1. Field of the Invention
The present invention relates to a bonding apparatus in which a bonding motor having a movable element and a motor main body is disposed on a mounting base, and the motor main body is provided to be movable in the opposite direction from the movable element when the movable element is driven, so that the reaction force applied to the mounting base as a result of the driving of the movable element is canceled out.
2. Description of the Related Art
In bonding apparatuses such as die bonding apparatuses which position chips and die-bond them to a board, wire bonding apparatuses which connect leads on a board and pads on chips by wires and the like, bonding work is performed while performing positioning of the board and chips or positioning of the leads and pads. A motor driving device is used for this positioning. For example, an XY table or the like on which the board or the like is mounted is driven to arbitrary positions.
When the load of an XY table or the like is thus driven using a motor driving device, vibration is, as a result of the reaction force caused by the driving of the load, applied to the mounting base of the bonding apparatus to which the motor driving device is attached. Especially in recent years, as precise, high-speed positioning has become a requirement in bonding apparatuses, the question of how to reduce vibration generated by an XY table or the like moving at a high speed has become a problem.
Elimination of the reaction movement of a motor driving device, which is used in a semiconductor manufacturing apparatus such as a bonding apparatus or the like and drives a driving body by means of a motor, is disclosed in Japanese Patent No. 2981999.
In this prior art, the motor main body and driving body are disposed on a mounting base so as to be movable in the direction of the common driving axes, so that the motor main body can move in the opposite direction from the driving body when the driving body is driven, thus causing the reaction force caused by the driving of the driving body to be cancelled. Furthermore, in this prior art, a pair of parallel guide rails are disposed between the mounting base and the motor main body in order to guide the movement of the motor main body. The motor main body that has moved in the opposite direction from the driving body is subsequently returned to its original position.
In such a motor device in which the reaction movement is eliminated, a mechanism that supports the weight of the motor main body itself and is also used to regulate the direction of movement of the motor main body (such as the pair of parallel guide rails indicated in the above-described prior art), is required. Accordingly, precision is required in the geometrical tolerance (flatness, degree of parallel orientation and the like) of the surface of the mounting base to which the two guide rails are attached. In some cases, furthermore, the movement of the motor main body may be hampered as a result of strain generated during the attachment of these guide rails, strain generated during the installation of the apparatus, thermal strain during the operation of the apparatus and the like.
As seen from the above, in the above-described prior art prior art, Japanese Patent No. 2981999, precision is required in the guide mechanism that guides the movement of the motor main body in order to eliminate any reaction movement in the bonding apparatus, and assembly, adjustment and the like are also bothersome, increasing the manufacturing cost.